The present invention relates to an axial piston pump or pumping machine having pistons guided in cylinders of a cylinder block and having channels for releasing the liquid pressure in the cylinders within the area between kidney-shaped control openings that are arranged in the distributor plate.
In order to obtain axial piston pumps with a low amount of vibration, fluctuation in pressure and noise, it is usual--for a specific, commonly used number of revolutions or for a specific feed pressure--to optimally adjust the arranged damping slot so that a low amount of fluctuation in pressure and of noise occur in this area. This optimization in a specific, for example, medium range in pressure and number of rotations has the disadvantage that a large amount of fluctuation in pressure arises when the swash plate or cylinder block are at full pivoting angle.
Axial piston pumps, which release the cylinder areas by bores which are axially arranged in the pistons, are known from the German patent 2 115 350 and the German laid-open document No. 2 147 045. The bores are connected with bores in the sliding blocks which receive the spherical ends of the pistons.
Such embodiments are complicated to produce, do not guarantee constant lubrication of the piston ends and transfer disturbing fluctuations in pressure, which arise in the cylinders, to the sliding blocks and the swash plate.
Accordingly, an object of the invention is to provide an axial piston pump or pumping machine which produces a low amount of disturbing fluctuation in pressure and noise, in areas of high and low pressure and rotational speeds.
Another object of the present invention is to provide a pumping arrangement of the foreqoing character which is simple in construction and may be econonmically maintained in service.
A further object of the present invention is to provide a pumping arrangement, as described, which has a substantially long operating life.